1. Field of the Invention
This invention relates to electric motor driven bilge pumps.
2. Description of the Prior Art
It has heretofore been proposed to provide pumps such as are illustrated in the patents to Rule, U.S. Pat. No. 3,250,828, Davenport et al., U.S. Pat. No. 3,408,942, and Yost, U.S. Pat. No. 2,320,708 which are typical of this type of pump but do not have liquid level responsive controls, must be externally controlled, do not provide adequate motor cooling and the packings to prevent access of liquid to the motor have serious limitations in use.
Lovett, in U.S. Pat. No. 2,669,934 shows a submersible automatic bilge pump but the float mechanism is lacking in reliability with continued use, the pump rotor is of unduly limited size, and the pump requires a large number of parts.
Rachocki, in U.S. Pat. No. 3,717,420, shows a float operated thermostatically controlled reed switch for motor energization, which is however of very low pump capacity.
Rachocki, U.S. Pat. No. 3,717,420, Vigren, U.S. Pat. No. 2,264,058 and Applin, U.S. Pat. No. 3,849,771 show reed switches actuated by floats which carry magnets.
The U.S. Pat. No. 3,408,942, to Davenport, shows a pump which requires a large number of parts and has a bushing which is subject to leaks, no float operated control being shown.
Conery et al., in U.S. Pat. No. 4,001,533 show a pump with a normally open microswitch having a magnet on a spring control arm positioned by weights.
Rupp, in U.S. Pat. No. 3,746,472, shows a pump housing with attached pump chamber but the structure is complex with a multitude of parts and no associated float responsive control.
Schumann, in U.S. Pat. No. 3,316,845, shows a bilge pump with a float control but the structure has a large number of parts and would be expensive to manufacture.
The structures of the prior art patents are relatively complex with a multitude of parts, are expensive to manufacture and assemble, lack the simple float control mechanism of the present invention, do not have any comparable continuously effective packing of the pump and motor bearing as herein disclosed, and do not provide adequate motor cooling.